feat(panel): günlük harcama ve dönem istatistikleri uç noktaları

- GET /periods/{id}/daily: dönemin her günü için 4 grubun harcaması
- GET /stats/periods: son dönemlerin harcanabilir/harcanan tutarı + toplam birikim
- Faz 7 adım planı

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/src/routes/stats.rs

@@ -0,0 +1,113 @@
+//! Panel (Dashboard) uç noktaları (hanenin tüm üyeleri):
+//!
+//! | Yöntem | Yol | İş |
+//! |---|---|---|
+//! | GET | `/api/periods/{id}/daily`     | dönemin her günü: 4 grubun harcaması |
+//! | GET | `/api/stats/periods?limit=12` | son dönemler (eskiden yeniye): harcanabilir, harcanan, birikime aktarılan + toplam birikim |
+
+use axum::{
+    Json,
+    extract::{Path, Query, State},
+};
+use mongodb::bson::Uuid;
+use serde::{Deserialize, Serialize};
+use ts_rs::TS;
+
+use crate::{
+    auth::AuthUser,
+    error::{AppError, AppResult},
+    models::period::PeriodStatus,
+    routes::budget::GroupAmounts,
+    services::{
+        calendar::{format_date, parse_date},
+        stats,
+    },
+    state::AppState,
+};
+
+#[derive(Serialize, TS)]
+#[ts(export, rename = "DaySpent")]
+pub struct DayDto {
+    /// `"YYYY-MM-DD"`
+    date: String,
+    /// O gün gruplara göre harcanan (kuruş)
+    spent: GroupAmounts,
+}
+
+pub async fn daily(
+    State(s): State<AppState>,
+    auth: AuthUser,
+    Path(id): Path<String>,
+) -> AppResult<Json<Vec<DayDto>>> {
+    let id = Uuid::parse_str(&id).map_err(|_| AppError::NotFound)?;
+    let days = stats::daily(&s.db, auth.household_id, id).await?;
+    Ok(Json(
+        days.into_iter()
+            .map(|d| DayDto {
+                date: d.date,
+                spent: d.spent.into(),
+            })
+            .collect(),
+    ))
+}
+
+#[derive(Deserialize)]
+pub struct StatsQuery {
+    limit: Option<usize>,
+}
+
+#[derive(Serialize, TS)]
+#[ts(export, rename = "PeriodStats")]
+pub struct StatsDto {
+    /// Kapanışlarda birikime aktarılanların toplamı (kuruş)
+    #[ts(type = "number")]
+    total_saved: i64,
+    /// Eskiden yeniye
+    periods: Vec<PeriodStatDto>,
+}
+
+#[derive(Serialize, TS)]
+#[ts(export, rename = "PeriodStat")]
+struct PeriodStatDto {
+    id: String,
+    name: String,
+    start_date: String,
+    /// Son gün, dahil
+    last_date: String,
+    status: PeriodStatus,
+    #[ts(type = "number")]
+    spendable: i64,
+    #[ts(type = "number")]
+    spent: i64,
+    /// Kapanmamışsa `null`
+    #[ts(type = "number | null")]
+    to_savings: Option<i64>,
+}
+
+pub async fn periods(
+    State(s): State<AppState>,
+    auth: AuthUser,
+    Query(q): Query<StatsQuery>,
+) -> AppResult<Json<StatsDto>> {
+    let st = stats::periods(&s.db, auth.household_id, q.limit.unwrap_or(12)).await?;
+    Ok(Json(StatsDto {
+        total_saved: st.total_saved,
+        periods: st
+            .periods
+            .into_iter()
+            .map(|x| {
+                let end = parse_date(&x.period.end_date).expect("geçerli bitiş tarihi");
+                PeriodStatDto {
+                    id: x.period.id.to_string(),
+                    name: x.period.name,
+                    start_date: x.period.start_date,
+                    last_date: format_date(end - time::Duration::days(1)),
+                    status: x.period.status,
+                    spendable: x.spendable,
+                    spent: x.spent,
+                    to_savings: x.period.to_savings,
+                }
+            })
+            .collect(),
+    }))
+}